The neurobiology of HIV dementia: implications for practice in South Africa.

In this review, the neuropathogenesis of HIV dementia (HIV-D) is discussed in the context of the local epidemic. HIV-D continues to be prevalent in the era of highly active anti-retroviral therapy. HIV neuro-invasion into the central nervous system may result in the development of separate HIV genotypes in an individual through compartmentalisation. The blood brain barrier continues to limit penetration of anti-retroviral drugs into the cerebrospinal fluid. Individuals with active neuro-inflammation appear to respond well to HAART. In some cases low grade neuro-degeneration persists with consequent clinical deterioration. In South Africa, the emergence of a sub-epidemic of HIV-D is being driven by various factors, including the incomplete coverage of HAART to all who need it, the late stage presentation of people living with HIV/AIDS (PLWHA) and a co-occurring methamphetamine epidemic. Differences in viral subtype do not appear to confer protection against HIV-D. Implications for PLWHA who are at risk for HIV-D in South Africa are explored, with a view to providing suggestions for improving practice and research into this area.